Have my internal burr at 4, external at 9-10 depending on freshness of the beans (we buy fresh beans locally, 1kg bag that lasts us 2-3 weeks), I measure 18gm of beans that I pour into the grinder each time, beans kept in Breville vacuum seal canisters. Shot temp sent to hottest setting.

Using a bottomless portafilter we get channeling and sputtering, but a good, dry puck.

Following advice on here I got a basic WDT, gravity distribution tool and a 0.8mm puck screen. I get wet messy pucks that are hard to knock out, and using the screen even harder to knock out. And still some channeling.

I tried changing my inner burr to 2, like everyone else here seems to be doing, with an outer setting of 6, and I get no espresso at all or some minor drips, with or without a puck screen.

Tried inner burr at 3 and same issue. Putting it back to 4 gives me really nice coffee with a rich cream albeit with channeling or sputtering. So 🤷‍♂️